The normal function and necessity for removing hydraulic valve lifters which have become frozen or stuck within their associated bores in the block and head of an internal combustion engine is well known in the art. This is exemplified by U.S. Pat. No. 2,882,591 to Grossman; U.S. Pat. No. 2,883,740 to Derby; U.S. Pat. No. 2,943,385 to Miller; U.S. Pat. No. 3,120,701 to Wilson; and U.S. Pat. No. 3,479,722 to Maness. These patents fully describe the normal operation of hydraulic valve lifters in an internal combustion engine and the problems which frequently occur that require their removal and replacement. The patents are further directed to various types of tools for mechanically breaking loose and extracting the lifters from the engine block. Most of these provide a tool having a head portion on which is mounted a plurality of expandable/retractable gripping members or fingers. The fingers are typically manipulated by a complicated force multiplying camming mechanism or he like on the head which is manually operated by suitable control linkage extending outwardly toward an opposite handle end of the tool.
The head end of the tool is adapted to be inserted into the lifter body which has several oil holes and one or more internal annular grooves therein for receiving snap ring retainers or the like normally employed to hold the lifter body and push rod components in operating assembly.
After removal of the push rod and snap rings the grooves are intended to be utilized for receiving the fingers of the extractor tool and the control linkage maniipulated externally thereof by the handle in an attempt to expand the fingers in tightly gripping relation to the lifter body, assuming the fingers and grooves have been properly aligned. Other tools of the prior art attempt to utilize one of the oil holes in the lifter for engagement by small pins on the finger of the tool. Because of the alignment problem the prior art tools are only intended to operate with the uppermost lifter groove or oil hole. Even then such alignment can only be accomplished blindly and primarily by "feel" requiring that the head of the tool be reciprocated within the lifter in a "hunting" exercise when attempting to locate the lifter groove or oil hole while concurrently expanding the fingers against the inner wall of the lifter body for placement into the groove or oil hole when alignment is finally achieved. This is usually an onerous, frustrating and time consuming procedure with no assurance that a dependable connection will be made between the tool and lifter body even after repeated attempts. Such connection of the tool can only be tested by further manipulations in an attempt to extract the lifter and because of the engagement of the fingers with only a single oil hole or snap ring groove this frequently results in slippage and their complete separation from the lifter. Severe damage to the lifter grooves or oil hole may also result making reinstallation of the tool and further attempts at extraction of the lifter nearly impossible. These prior art extractors employ very complex structures which are difficult and expensive to manufacture and to use with any degree of dependability or success. Consequently, it is recognized that an improved extractor tool for the quick, dependable removal of hydraulic value lifters could be provided having a greatly simplified structure which is easily and conveniently installed with the gripping members thereof being automatically and precisely alignable with more than a single groove in the lifter for establishing a dependable connection capable of withstanding the forces required to effect withdrawal of the lifter from an engine block or head. Accordingly, the present invention is intended to overcome the problems as set forth above.